Matte multilayer polyester film

Abstract

A matt multiplayer polyester film includes at least to layers A and B, wherein the polyester of the layer A is a polyester with a glass transition temperature TgA of 30 to 70° C. consisting of (a) 60 to 95 wt % of a polyester and (b) 5 to 40 wt % of an incompatible resin, while the main one of the polyesters of the layer B is a copolyester with a melting point TmB of 120 to 210° C., the surface glossiness of the layer A being less than 50%.

1 . A matt multilayer polyester film comprising at least two layers A and B, wherein the polyester of the layer A is a polyester with a glass transition temperature TgA of 30 to 70° C. consisting of (a) 60 to 95 wt % of a polyester and (b) 5 to 40 wt % of an incompatible resin, while a main one of the polyesters of the layer B is a copolyester with a melting point TmB of 120 to 210° C., and surface glossiness of the layer A less than 50%. 
   
   
       2 . The matt multilayer polyester film according to  claim 1 , wherein the polyester of the layer A is a composition consisting of 60 to 90 wt % of the polyester (a), 5 to 20 wt % of the incompatible resin (b), and 5 to 20 wt % of a thermoplastic resin (c) and/or an inorganic filler (d). 
   
   
       3 . The matt multilayer polyester film according to  claim 1 , wherein the incompatible resin (b) is a long chain aliphatic dicarboxylic acid copolyester. 
   
   
       4 . The matt multilayer polyester film according to  claim 1 , wherein the polyesters of the layer B are copolyesters, each consisting of dicarboxylic acids including 90 mol % or more of an aromatic dicarboxylic acid and a long chain aliphatic dicarboxylic acid and glycols including 90 mol % or more of ethylene glycol and 1,4-butadiol, respectively as monomer components. 
   
   
       5 . The matt multilayer polyester film according to  claim 1 , wherein at least one of the polyesters of the layer B satisfies the following (1) and (2):
 (1) an amount of the aromatic dicarboxylic acid as a component is 60 to 99 mol % and an amount of the long chain aliphatic dicarboxylic acid as a component is 1 to 40 mol %, respectively, based on the amount of all the dicarboxylic acids; and   (2) the glycols as components include at least one or more glycols respectively with less than 10 carbon atoms.   
   
   
       6 . The matt multilayer polyester film according to  claim 1 , wherein a dimer content of the long chain aliphatic dicarboxylic acid as a component is 70 to 90 wt % and trimer content is 10 to 30 wt %. 
   
   
       7 . The matt multilayer polyester film according to  claim 1 , wherein the long chain aliphatic dicarboxylic acid as a component is a dimer acid or a dimer acid derivative. 
   
   
       8 . The matt multilayer polyester film according to  claim 1 , which has a plane orientation coefficient of 0 to 0.05. 
   
   
       9 . A laminate comprising the matt multilayer polyester film set forth in  claim 1  and a wallpaper board substrate laminated on each other with the layer A of the matt multilayer polyester film kept as an outer surface. 
   
   
       10 . The laminate according to  claim 9 , wherein the wallpaper board substrate contains a polyolefin resin layer or a polyvinyl chloride resin layer.